<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Leal, Sofia</style></author><author><style face="normal" font="default" size="100%">González-Pérez, Aranzazu</style></author><author><style face="normal" font="default" size="100%">Vasquez-Piqué, Javier</style></author><author><style face="normal" font="default" size="100%">Spiecker, Heinrich</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">Pereir, Helena</style></author><author><style face="normal" font="default" size="100%">GONZÁLEZ-PÉREZ, ARANTZAZU</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">cork oak wood a hard material to sample and to measure</style></title><secondary-title><style face="normal" font="default" size="100%">Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Anatomy</style></keyword><keyword><style  face="normal" font="default" size="100%">growth rings</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword><keyword><style  face="normal" font="default" size="100%">sampling</style></keyword><keyword><style  face="normal" font="default" size="100%">wood growth</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Universidad de Huelva</style></publisher><pub-location><style face="normal" font="default" size="100%">Huelva</style></pub-location><pages><style face="normal" font="default" size="100%">456</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Different studies within the Suberwood project required measurements of wood growth in cork oak trees (Quercus suber L.), including tree ring analysis, as a basis to analyse the influence on tree growth of stress effects, namely those deriving from climatic conditions (i.e. water deficit) or from the cork extraction. The research partners have experienced serious difficulties in these tasks and some examples are presented and discussed. The first difficulty regards sampling because cork oak harvesting is forbidden in Portugal and advantage has to be taken from legally authorised tree fellings. The available material therefore consists mainly in thinning material (young trees), dead or diseased trees, and trees with damaged stems due to improper cork harvesting, which are useless for such studies. In most cases the information concerning the stand management is lacking, namely regarding the time of cork extraction and of other silvicultural operations (i.e. pruning). Therefore the experimental design regarding treatments and repetitions often cannot follow the conventional statistical guidelines. The cork oak wood also has anatomical and structural features that bring considerable complexity for ring definition. The wood has a semi-ring porosity with poor growth ring definition and it is very difficult, and frequently impossible, to accurately identify growth rings and to link measurements to a certain year. Additionally cork extraction disturbs wood growth and anatomy. Different observation approaches were tested: overall microscopical observations, continuous radial measurement of vessel dimensions and density, continuous radial microdensitometric profiles, cambial wounding. The use of non-destructive samples (i.e. cores or small wood samples) adds to the uncertainty encountered. Stem discs offer a better observation but differences among different radii are often very large.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">GONZÁLEZ-PÉREZ, ARANTZAZU</style></author><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">TAPIAS, RAÚL</style></author><author><style face="normal" font="default" size="100%">FERNÁNDEZ, MANUEL</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author><author><style face="normal" font="default" size="100%">GONZÁLEZ-PÉREZ, ARANTZAZU</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">SEASONAL PATTERN OF PHYSIOLOGICAL STATE IN A CORK OAK (QUERCUS SUBER L.) STAND IN HUELVA (SPAIN)</style></title><secondary-title><style face="normal" font="default" size="100%">Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">fluorescenc</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">water potential</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Universidad de Huelva</style></publisher><pub-location><style face="normal" font="default" size="100%">Huelva</style></pub-location><pages><style face="normal" font="default" size="100%">456</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The seasonal pattern of the physiological state of Quercus suber is determined by different ecological factors, and it affects to the growth of the species. The main objective of this study is to know the seasonal pattern of water potential, photosynthesis and fluorescence in four Quercus suber L. trees and to relate these values with ecological factors during two years. In this time there were three critical periods, the first one the end of the dry period where the water potential descends to values less than -3MPa and the photosynthesis to 0.781 µmol CO2m-2 s-1Quercus suber, physiology, water potential, photosynthesis, fluorescence. . The second critical period is located in period of change of the leaf, between the months of March and May. The third critical period occurred due to the freezes and drought of the year 2005, that produced strong damages in the PSII.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>47</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">GONZÁLEZ-PÉREZ, ARANTZAZU</style></author><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">TAPIAS, RAÚL</style></author><author><style face="normal" font="default" size="100%">FERNÁNDEZ, MANUEL</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author><author><style face="normal" font="default" size="100%">GONZÁLEZ-PÉREZ, ARANTZAZU</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">SEASONAL PATTERN OF PHYSIOLOGICAL STATE IN A CORK OAK (QUERCUS SUBER L.) STAND IN HUELVA (SPAIN)</style></title><secondary-title><style face="normal" font="default" size="100%">Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">fluorescenc</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">water potential</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">Universidad de Huelva</style></publisher><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The seasonal pattern of the physiological state of Quercus suber is determined by different ecological factors, and it affects to the growth of the species. The main objective of this study is to know the seasonal pattern of water potential, photosynthesis and fluorescence in four Quercus suber L. trees and to relate these values with ecological factors during two years. In this time there were three critical periods, the first one the end of the dry period where the water potential descends to values less than -3MPa and the photosynthesis to 0.781 µmol CO2m-2 s-1Quercus suber, physiology, water potential, photosynthesis, fluorescence. . The second critical period is located in period of change of the leaf, between the months of March and May. The third critical period occurred due to the freezes and drought of the year 2005, that produced strong damages in the PSII.</style></abstract><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;periodical: Suberwood2005: New challenges for integration of cork oak forests and products, Scientific and Technical Conference, Huelva, Spain, 20, 21 and 22 October 2005.&lt;br/&gt;pub-location: Huelva</style></notes></record></records></xml>